1 // SPDX-License-Identifier: GPL-2.0 2 3 /* 4 * Core routines for interacting with Microsoft's Hyper-V hypervisor, 5 * including hypervisor initialization. 6 * 7 * Copyright (C) 2021, Microsoft, Inc. 8 * 9 * Author : Michael Kelley <mikelley@microsoft.com> 10 */ 11 12 #include <linux/types.h> 13 #include <linux/acpi.h> 14 #include <linux/export.h> 15 #include <linux/errno.h> 16 #include <linux/version.h> 17 #include <linux/cpuhotplug.h> 18 #include <asm/mshyperv.h> 19 20 static bool hyperv_initialized; 21 22 int hv_get_hypervisor_version(union hv_hypervisor_version_info *info) 23 { 24 hv_get_vpreg_128(HV_REGISTER_HYPERVISOR_VERSION, 25 (struct hv_get_vp_registers_output *)info); 26 27 return 0; 28 } 29 EXPORT_SYMBOL_GPL(hv_get_hypervisor_version); 30 31 static int __init hyperv_init(void) 32 { 33 struct hv_get_vp_registers_output result; 34 u64 guest_id; 35 int ret; 36 37 /* 38 * Allow for a kernel built with CONFIG_HYPERV to be running in 39 * a non-Hyper-V environment, including on DT instead of ACPI. 40 * In such cases, do nothing and return success. 41 */ 42 if (acpi_disabled) 43 return 0; 44 45 if (strncmp((char *)&acpi_gbl_FADT.hypervisor_id, "MsHyperV", 8)) 46 return 0; 47 48 /* Setup the guest ID */ 49 guest_id = hv_generate_guest_id(LINUX_VERSION_CODE); 50 hv_set_vpreg(HV_REGISTER_GUEST_OS_ID, guest_id); 51 52 /* Get the features and hints from Hyper-V */ 53 hv_get_vpreg_128(HV_REGISTER_PRIVILEGES_AND_FEATURES_INFO, &result); 54 ms_hyperv.features = result.as32.a; 55 ms_hyperv.priv_high = result.as32.b; 56 ms_hyperv.misc_features = result.as32.c; 57 58 hv_get_vpreg_128(HV_REGISTER_FEATURES_INFO, &result); 59 ms_hyperv.hints = result.as32.a; 60 61 pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, hints 0x%x, misc 0x%x\n", 62 ms_hyperv.features, ms_hyperv.priv_high, ms_hyperv.hints, 63 ms_hyperv.misc_features); 64 65 hv_identify_partition_type(); 66 67 ret = hv_common_init(); 68 if (ret) 69 return ret; 70 71 ret = cpuhp_setup_state(CPUHP_AP_HYPERV_ONLINE, "arm64/hyperv_init:online", 72 hv_common_cpu_init, hv_common_cpu_die); 73 if (ret < 0) { 74 hv_common_free(); 75 return ret; 76 } 77 78 if (ms_hyperv.priv_high & HV_ACCESS_PARTITION_ID) 79 hv_get_partition_id(); 80 81 ms_hyperv_late_init(); 82 83 hyperv_initialized = true; 84 return 0; 85 } 86 87 early_initcall(hyperv_init); 88 89 bool hv_is_hyperv_initialized(void) 90 { 91 return hyperv_initialized; 92 } 93 EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized); 94